I can tell you about my childhood, but I don't want to give you a wrong impression. Whilst I was noticeably different (to the extent that back in the 1980's there were calls for me to be assessed and when I was diagnosed my mum didn't bat an eyelid) I was (and still am) what would be classed as high functioning. By which, on a personal level, I could attend a mainstream school (though secondary school and the larger primary school I attended age 10 -11 were much harder and more confusing than the small village primary I attended between the ages of 6 -10. Plus, I could have conversations with people (tangential speech, very fast way of talking, rarely initiating and coming across as being very serious not withstanding. So, if your child is more severely on the spectrum I don't want to give you the wrong impression.
Ok, I'll begin :
One thing that does sort of jolt me up and then DH has to remind me I'm still like it in a lot of ways, is my lack of awareness with a lot of things. I don't mean when reading things, I can be quite perceptive in that respect, but in my ability to take note of what is going on around me and to be aware of what others are doing/saying. Things that you would expect a child to remember, I have no memory of. I cannot remember any birthdays before the age of 7 or 8. Apart from a brief scene when I was 3 I can't remember any Christmases before this time. Any trips out, my first day of school, The Falklands War (not that I'd expect a 6 year old to be much aware of that, but I only knew about it years later), I cannot recall. But, I can remember the green light shining on my socks in a fairground ride. I can remember the flat cobbled tiles on the street and how my feet just fit into them. I can remember my dad bringing the coal in when I was 18 months. So, big events held little importance for me, what I focused on was the small, the seemingly trivial. As I got older this difficulty in awareness lessened, but it continued and still applies today. At 15 I had an accident in Church (I was toilet trained at a normal time but due to mainly communication problems continued to have accidents until my mid to late teens) and was about to walk up the aisle for Communion, completely unthinking that others would notice, before my dad saw me and stopped me. More recently ,I have missed whole shouting matches within a few feet of me, have not noticed people talking to me, or if I have noticed have often not been able to respond.
This next bit is hard to write as it sounds so negative and I want to reassure you that this is just me and not every person on the spectrum feels like this, but I do not feel much emotion or often realise that others will be upset at something unless it is specifically pointed out to them. That doesn't mean I don't have sympathy and that I won't comfort them. Also, if someone is crying or arguing next to me, even if it has nowt to do with me, I will start crying, which indicates genuine empathy on my part, rather than presumed empathy. As a 9 year old I watched a government safety film that had showed the deaths of two family members and I was genuinely surprised at the mum grieving . I have never really got upset at big things, but trivial things can really throw me. Eg they have moved the newspaper rack in my local supermarket. Whenever I went in I would turn to right a little and go straight to the newspapers. Now they have shifted them and it doesn't feel right. Same as when I was a child, my dad being lucky to survive a car accident led to me feeling nothing, the bruises on his head made me revulsed.
Speech, well, I was verbal and to the extent that you could have a conversation with me, but there are still difficulties. I struggle with initiating and now I will rehearse in my mind what to say if I want to initiate talking. This initiating also affects other aspects of my life as well. As a child I would rarely initiate talking. I woudl speak very fast, I've slowed down to a normal pitch now. Today, you wouldn't think there was anything odd, apart from a tendency to perseverate on one topic, talk of things out of context, have difficulties knowing when to enter a group conversation and having tangential speech. My use of language has always subscribed to the Gilberg criteria for Aspergers of "superficially excellent expressive language" (I am paraphrasing here). As a child I would often speak to other adults through my mum and now I often do it through my husband.
I had obsessions and still have obsessions which were - and still are - very important to me and, in many ways, did end up helping me. But with hindsight I can see where they could cause difficulties or concerns sometimes. To give you one example, when I was about 9 I kept getting the same book out of the library for about 6 months (mum stopped me in the end). It had a red silky ribbon as part of its attraction .
I've not covered everything by a long shot, but this post is getting rather long, so I'll just mention the stims. Sometimes I stim because it feels nice and relaxing. Other times I stim because I'm getting wound up over something and I can't block the worrying/overloading thing out. And sometimes I don't know why I stim, it just happens.